How to determine if Simultaneous Multithreading (SMT) is being used/ enabled

Products

• SYSVIEW Performance Management

Issue/Introduction

How to determine if SMT is enabled and being used  ?

Cause

Originally asked in R15.0 where hyper APAR SO12995 states the problem it corrects can only occur if Simultaneous Multithreading (SMT)  
is in use, where there are multiple threads per core.    Information could be applicable to ALL releases of SYSVIEW.

Resolution

IBM LOADxx parmlib option PROCVIEW CORE|CPU enables/disables SMT for the life of the IPL
• PROCVIEW CORE on z13 enables SMT support
• IPL required to switch between PROCVIEW CPU and CORE

Additional Information

Simultaneous multithreading (SMT) allows two active instruction  streams per core, each dynamically sharing the core's execution 
resources. SMT is available on the z13 for workloads running on the IFL and the IBM z Integrated Information Processor (zIIP). 
SMT is disabled by default.